Properties of An Iridescent Virus From the Beetle, Serioesthis Pruinosa

Abstract

The recently described iridescent virus from Sericesthis (SIV) is closely related to Tipula iridescent virus (TIV). TIV and SIV are morphologically similar and have similar sedimentation coefficients (S20 w = 2200 s). SIV differs from TIV serologically and in DNA content. Large yields of purified SIV, of the order of 2 mg virus protein per pupa, may be obtained from the wax moth, Galleria mellonella. SIV is thermolabile, ether- and chloroform-resistant, and its infectivity is retained after exposure to either pH 3.0 or 10.5 for 3 hr. SIV shares these properties with the adenovirus group. Particle counts of SIV in the electron microscope have been related to infectivity, to total protein, and to absorbance at 260 m/[mu]. 1 absorbance unit represents 0.056 mg SIV protein per millilitre, and this is equivalent to 1.8 x 109 particles. The total particle/infective particle ratio is approximately 11. SIV developed in Galleria larvae kept at 22[degree]C, but not at 28[degree]C.